diff --git a/include/llvm/Target/TargetInstrInfo.h b/include/llvm/Target/TargetInstrInfo.h
index 5c5f0e151c1..30a184f3b1b 100644
--- a/include/llvm/Target/TargetInstrInfo.h
+++ b/include/llvm/Target/TargetInstrInfo.h
@@ -143,7 +143,7 @@ public:
   ///
   virtual MachineInstr *
   convertToThreeAddress(MachineFunction::iterator &MFI,
-                   MachineBasicBlock::iterator &MBBI, LiveVariables &LV) const {
+                   MachineBasicBlock::iterator &MBBI, LiveVariables *LV) const {
     return 0;
   }
 
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index f6e2f55b306..d2e5288d34b 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -378,27 +378,6 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
                     if (LV) {
                       // Update live variables
                       LV->instructionChanged(mi, NewMI); 
-                    } else {
-                      // Update flags manually
-                      for (unsigned i = 0, e = mi->getNumOperands();
-                           i != e; ++i) {
-                        MachineOperand &MO = mi->getOperand(i);
-                        if (MO.isRegister() && MO.getReg() &&
-                          TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
-                          unsigned Reg = MO.getReg();
-                          if (MO.isDef()) {
-                            if (MO.isDead()) {
-                              MO.setIsDead(false);
-                              NewMI->addRegisterDead(Reg, TRI);
-                            }
-                          }
-                          
-                          if (MO.isKill()) {
-                            MO.setIsKill(false);
-                            NewMI->addRegisterKilled(Reg, TRI);
-                          }
-                        }
-                      }
                     }
                     
                     mbbi->insert(mi, NewMI);           // Insert the new inst
@@ -424,7 +403,7 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
                 assert(TID.getOperandConstraint(i, TOI::TIED_TO) == -1);
 #endif
 
-              MachineInstr *NewMI = TII->convertToThreeAddress(mbbi, mi, *LV);
+              MachineInstr *NewMI = TII->convertToThreeAddress(mbbi, mi, LV);
               if (NewMI) {
                 DOUT << "2addr: CONVERTING 2-ADDR: " << *mi;
                 DOUT << "2addr:         TO 3-ADDR: " << *NewMI;
@@ -481,30 +460,6 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) {
 
             if (LV->removeVirtualRegisterDead(regB, mbbi, mi))
               LV->addVirtualRegisterDead(regB, prevMi);
-          } else {
-            // Manually update kill/dead flags.
-            bool RemovedKill = false;
-            bool RemovedDead = false;
-            for (unsigned i = 0, e = mi->getNumOperands(); i != e; ++i) {
-              MachineOperand &MO = mi->getOperand(i);
-              if (MO.isRegister() && MO.isKill() && MO.getReg() == regB) {
-                MO.setIsKill(false);
-                RemovedKill = true;
-                break;
-              } 
-              
-              if (MO.isRegister() && MO.isDef() && MO.getReg() == regB) {
-                MO.setIsDead(false);
-                RemovedDead = true;
-              }
-              
-              if (RemovedKill && RemovedDead) break;
-            }
-            
-            if (RemovedKill)
-              prevMi->addRegisterKilled(regB, TRI);
-            if (RemovedDead)
-              prevMi->addRegisterDead(regB, TRI);
           }
           
           // Replace all occurences of regB with regA.
diff --git a/lib/Target/ARM/ARMInstrInfo.cpp b/lib/Target/ARM/ARMInstrInfo.cpp
index f9f10bafe3e..61e4f26a16a 100644
--- a/lib/Target/ARM/ARMInstrInfo.cpp
+++ b/lib/Target/ARM/ARMInstrInfo.cpp
@@ -191,7 +191,7 @@ static unsigned getUnindexedOpcode(unsigned Opc) {
 MachineInstr *
 ARMInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
                                     MachineBasicBlock::iterator &MBBI,
-                                    LiveVariables &LV) const {
+                                    LiveVariables *LV) const {
   if (!EnableARM3Addr)
     return NULL;
 
@@ -300,22 +300,25 @@ ARMInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
     if (MO.isRegister() && MO.getReg() &&
         TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
       unsigned Reg = MO.getReg();
-      LiveVariables::VarInfo &VI = LV.getVarInfo(Reg);
-      if (MO.isDef()) {
-        MachineInstr *NewMI = (Reg == WBReg) ? UpdateMI : MemMI;
-        if (MO.isDead())
-          LV.addVirtualRegisterDead(Reg, NewMI);
-      }
-      if (MO.isUse() && MO.isKill()) {
-        for (unsigned j = 0; j < 2; ++j) {
-          // Look at the two new MI's in reverse order.
-          MachineInstr *NewMI = NewMIs[j];
-          if (!NewMI->readsRegister(Reg))
-            continue;
-          LV.addVirtualRegisterKilled(Reg, NewMI);
-          if (VI.removeKill(MI))
-            VI.Kills.push_back(NewMI);
-          break;
+      
+      if (LV) {
+        LiveVariables::VarInfo &VI = LV->getVarInfo(Reg);
+        if (MO.isDef()) {
+          MachineInstr *NewMI = (Reg == WBReg) ? UpdateMI : MemMI;
+          if (MO.isDead())
+            LV->addVirtualRegisterDead(Reg, NewMI);
+        }
+        if (MO.isUse() && MO.isKill()) {
+          for (unsigned j = 0; j < 2; ++j) {
+            // Look at the two new MI's in reverse order.
+            MachineInstr *NewMI = NewMIs[j];
+            if (!NewMI->readsRegister(Reg))
+              continue;
+            LV->addVirtualRegisterKilled(Reg, NewMI);
+            if (VI.removeKill(MI))
+              VI.Kills.push_back(NewMI);
+            break;
+          }
         }
       }
     }
diff --git a/lib/Target/ARM/ARMInstrInfo.h b/lib/Target/ARM/ARMInstrInfo.h
index be95d56a69a..34c547028aa 100644
--- a/lib/Target/ARM/ARMInstrInfo.h
+++ b/lib/Target/ARM/ARMInstrInfo.h
@@ -153,7 +153,7 @@ public:
 
   virtual MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
                                               MachineBasicBlock::iterator &MBBI,
-                                              LiveVariables &LV) const;
+                                              LiveVariables *LV) const;
 
   // Branch analysis.
   virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 218487e94bf..969a05c580a 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -978,7 +978,7 @@ static bool hasLiveCondCodeDef(MachineInstr *MI) {
 MachineInstr *
 X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
                                     MachineBasicBlock::iterator &MBBI,
-                                    LiveVariables &LV) const {
+                                    LiveVariables *LV) const {
   MachineInstr *MI = MBBI;
   // All instructions input are two-addr instructions.  Get the known operands.
   unsigned Dest = MI->getOperand(0).getReg();
@@ -1066,10 +1066,12 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
       
       MFI->insert(MBBI, Undef);
       MFI->insert(MBBI, Ins);            // Insert the insert_subreg
-      LV.instructionChanged(MI, NewMI);  // Update live variables
-      LV.addVirtualRegisterKilled(leaInReg, NewMI);
+      if (LV) {
+        LV->instructionChanged(MI, NewMI);  // Update live variables
+        LV->addVirtualRegisterKilled(leaInReg, NewMI);
+      }
       MFI->insert(MBBI, NewMI);          // Insert the new inst
-      LV.addVirtualRegisterKilled(leaOutReg, Ext);
+      if (LV) LV->addVirtualRegisterKilled(leaOutReg, Ext);
       MFI->insert(MBBI, Ext);            // Insert the extract_subreg      
       return Ext;
     } else {
@@ -1180,7 +1182,7 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
   if (!NewMI) return 0;
 
   NewMI->copyKillDeadInfo(MI);
-  LV.instructionChanged(MI, NewMI);  // Update live variables
+  if (LV) LV->instructionChanged(MI, NewMI);  // Update live variables
   MFI->insert(MBBI, NewMI);          // Insert the new inst    
   return NewMI;
 }
diff --git a/lib/Target/X86/X86InstrInfo.h b/lib/Target/X86/X86InstrInfo.h
index d24156531e4..b38b618cb5f 100644
--- a/lib/Target/X86/X86InstrInfo.h
+++ b/lib/Target/X86/X86InstrInfo.h
@@ -295,7 +295,7 @@ public:
   ///
   virtual MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
                                               MachineBasicBlock::iterator &MBBI,
-                                              LiveVariables &LV) const;
+                                              LiveVariables *LV) const;
 
   /// commuteInstruction - We have a few instructions that must be hacked on to
   /// commute them.